Dyspepsia (cont.)

Jay W. Marks, MD

Jay W. Marks, MD, is a board-certified internist and gastroenterologist. He graduated from Yale University School of Medicine and trained in internal medicine and gastroenterology at UCLA/Cedars-Sinai Medical Center in Los Angeles.

William C. Shiel Jr., MD, FACP, FACR

Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

How is dyspepsia diagnosed (indigestion)?

Dyspepsia is diagnosed primarily on the basis of typical symptoms and the
exclusion of non-functional gastrointestinal diseases (including acid-related
diseases), non-gastrointestinal diseases, and psychiatric illness. There are
tests for identifying abnormal gastrointestinal function directly, but they are
limited in their ability to do so.

Exclusion of other diseases

Exclusion of non-functional gastrointestinal disease

As always, a detailed history from the patient and a physical examination frequently will suggest the cause of dyspepsia. Routine screening blood tests often are performed looking for clues to unsuspected diseases. Examinations of stool also are a part of the evaluation since they may reveal infection, signs of inflammation, or blood and direct further diagnostic testing. Sensitive stool testing (antigen/antibody) for
Giardia lamblia would be reasonable because this parasitic infection is common and can be acute or chronic. Some physicians do blood testing for
celiac disease (sprue), but the value of doing this is unclear. (Moreover, if an
EGD is planned, biopsies
of the duodenum usually will make the diagnosis of celiac disease.) If bacterial
overgrowth of the small intestine is being considered, breath hydrogen testing can be considered.

There are many tests to
exclude non-functional gastrointestinal diseases. The primary issue, however, is
to decide which tests are reasonable to perform. Since each case is individual,
different tests may be reasonable for different patients. Nevertheless, certain
basic tests are often performed to exclude non-functional gastrointestinal
disease. These tests identify anatomic (structural) and histological
(microscopic) diseases of the esophagus, stomach, and intestines.

Both X-rays and endoscopies can identify anatomic diseases. Only endoscopies,
however, can diagnose histological diseases because biopsies (samples of tissue)
can be taken during the procedure. The X-ray tests include:

The esophagram and video-fluoroscopic swallowing
study for examining the esophagus

The upper gastrointestinal series for examining the
stomach and duodenum

Endoscopy also is available to examine the small intestine, but this type
of endoscopy is complex, not widely available, and of unproven value in
dyspepsia.

For examination of the small intestine, there is also a capsule containing a tiny
camera and transmitter that can be swallowed (capsule
endoscopy). As the capsule travels through the
intestines, it transmits pictures of the inside of the intestines to an external
recorder for later review. The capsule is not widely available and its value,
particularly in dyspepsia, has not yet been proven.

Newer endoscopes, similar to those used for EGD and colonoscopy are available
that allow the entire small intestine to be examined. Unlike the capsule,
however, the endoscope has channels in it that allow instruments to be passed
into the intestine to collect samples of tissue (biopsies) and to treat abnormal
findings such as polyps.

X-rays are easier to perform and less costly than endoscopies. The skills necessary
to perform gastrointestinal X-rays, however, are becoming rare among radiologists
because they are doing them less often. Therefore, the quality of the X-rays
often is not as high as it used to be, and, as a result, CT scans of the small intestine are replacing small intestinal X-rays. As noted previously, endoscopies have an
advantage over X-rays since at the time of endoscopies, biopsies can be taken to
diagnose or exclude histological diseases, something that X-rays cannot do.

Exclusion of acid-related gastrointestinal diseases

Because they are so
common, the most important non-functional gastrointestinal diseases to exclude
are acid-related diseases that cause inflammation and ulceration of the
esophagus, stomach, and duodenum. Infection of the stomach with Helicobacter
pylori, an infection that is closely associated with some acid-related diseases,
is included in this group. It is not clear, however, how often Helicobacter
pylori causes dyspepsia. Moreover, the only way of excluding this bacterium as a
cause of dyspepsia in a particular patient is by eliminating the infection (if
it is present) with appropriate antibiotics. If dyspepsia is substantially
improved by eradication, it is likely that the bacterium was responsible.
Helicobacter pylori infection also can be diagnosed (or excluded) by blood
tests, biopsy of the stomach, urea breath test, or a stool test.

Endoscopy is a good way of diagnosing or excluding
acid-related inflammation. If no signs of inflammation are present, acid-related diseases are
unlikely. Nevertheless, some patients without signs of inflammation respond to potent
and prolonged suppression of acid, suggesting that acid is causing their
dyspepsia. Therefore, many physicians will use potent suppression of acid in dyspepsia as
a means to both treat and diagnose. Thus, if dyspepsia improves
substantially (more than 50% to 75%) with suppression of acid, they consider it likely that acid is
responsible for the dyspepsia. For this purpose, it is important to use potent
acid suppression with proton pump inhibitors (PPIs), such as:

Treatment often is given at higher than
recommended doses for 12 weeks or more before a decision is made about the
effect of treatment on the symptoms. (A short course for just a few days or
weeks is not enough.) If the symptoms of dyspepsia do not improve, it even may
be reasonable to check the amount of acid produced by the stomach (and also the
reflux of acid into the esophagus) by 24 hour ph monitoring to be certain that
the acid-suppressing drugs are effectively suppressing acid. (Up to 10% of
patients are resistant to the effects of even the PPIs.)

Exclusion of non-gastrointestinal disease

Patients with dyspepsia often
undergo abdominal ultrasonography (US), computerized tomography (CT or CAT
scans), or magnetic resonance imaging (MRI). These tests are used primarily to
diagnose non-intestinal diseases. (Although the tests also are capable of
diagnosing intestinal diseases, their value for this purpose is limited. X-ray
and endoscopy are better.) It is important to realize that US, CT, and MRI are
powerful tests and may uncover abnormalities that are unrelated to dyspepsia.
The most common example of this is the finding of gallstones that, in fact, are
causing no symptoms. (At least up to 50% of gallstones cause no symptoms.) This can cause
a problem if the gallstones are assumed to be causing the dyspepsia. Surgical
removal of the gallbladder with its gallstones (cholecystectomy) is unlikely to
relieve the dyspepsia. (Cholecystectomy would be expected to relieve only the
characteristic symptoms that gallstones can cause.) Additional tests to exclude
non-gastrointestinal diseases may be appropriate in certain specific situations,
although certainly not in most patients.

Exclusion of psychiatric disease

The possibility of psychiatric
(psychological or psychosomatic) illness often arises in patients with dyspepsia
because the symptoms are subjective and no objective abnormalities can be
identified. Psychiatric illness may complicate dyspepsia, but it is unclear if
psychiatric illness causes dyspepsia. If there is a possibility of psychiatric
illness, a psychiatric evaluation is appropriate.